Bore inspection?The AFV ASSOCIATION was formed in 1964 to support the thoughts and research of all those interested in Armored Fighting Vehicles and related topics, such as AFV drawings. The emphasis has always been on sharing information and communicating with other members of similar interests; e.g. German armor, Japanese AFVs, or whatever.Go to page 1, 2Next

Bore sighting. He looks through a little in-bore device to align the center of the physical gun tube on a boresight panel 1200m down range.

He then uses hand and finger signals to inform the gunner which way to manually move the turret/gun until the crosshairs are at a certain spot on the boresight panel.

The gunner then adjusts his sights until his reticle (crosshairs) are at the exact same spot as the bore sight device.

The old 105mm bore sight device was called the Pye-Watson, the 120mm was an M26E or something along those lines, but many still called it the Pye-Watson.

There's a similar device for the .50 cal called the Anderson Device. It is used to make sure the commander's .50 sight is aligned as well.

There's normally a long red flag attached that is just like an aircraft's "REMOVE BEFORE FLIGHT" tag except it says "REMOVE BEFORE FIRING". There have been several incidents where the crew forgets to remove the Pye-Watson and sends it down range, normally with part of the gun tube and MRS.

'Well, when we used to boresight, we'd used to get oop at 5 o'clock, four hours before the sun went down, then go down to the range and tape two bits o' string across the end o' the moozle and peer through the breech wit' a pair o' binoculars through a ring-shaped deviced centered on the chambere and sight on a distant right angle...say, a patient window at Ireland Army Hospital at Ft. Knox."

"Aye, aye"....

"Now, you try and tell the young people that today....they won't bloody believe ya',"

You must have been part of the new mekinized army. back in the old days we'd pull a hair from the drag horse on the team and use chawin tabac to hold it in placein the notches on the muzzle

Yap, definitely that is the way we used to "zero-in" the armament of BMP-1 or BPzV Svatava. Instead "chawin tabac" we used small pieces of magnet, instead "a hair from the drag horse" we used thread ...
There was a metal "diopter" piece â€“ typical shape of German "potato masher" stick grenade to be inserted into gun chamber.... Optic device "L" had to be inserted into the PKT MG muzzle - with red flaggie too.

I did it many, many times before live fire trg as a guy responsible for...everything

Here I am, making the 'boresight face', but using a modified 'bail-out' cord, so I can talk to my gunner thru the intercom. No 'gang sign' directions,.....precision boresighting thru positive communication.

Notice my Boresight instructions on front slope,.....I'm doing final comfirmation following completion of the proceedure.

BTW: The string method is for dinosaurs. The 105mm MBD was the 'Pye-Watson'. The 120mm is known as the 'Lensar'(sp?).

As of the '70's (or maybe even the '80's, I don't know when the fancy-schmancy optical thingy's were introduced) what y'all are quaintly calling the "old string method" was not "field expedient" it was simply "THE boresight procedure" and the only known way it way it was done. There were a couple of variations of sighting down the chamber from the inside. One involved removing the firing pin mechanism from 90mm's (I believe) and there was also a round template thingy with a female receptacle that could receive the objective end of one side of a binocular that you could stick in the open breech (better method, less squinting) and both had the advantage of letting you just speak to the gunner so he could lay the crosshairs of the string on the selected right angle.

Then the gunner aligns the reticle and you have your rough sights set and you're ready to go to the range and bust some caps for zero.

As of the '70's (or maybe even the '80's, I don't know when the fancy-schmancy optical thingy's were introduced) what y'all are quaintly calling the "old string method" was not "field expedient" it was simply "THE boresight procedure" and the only known way it way it was done. There were a couple of variations of sighting down the chamber from the inside. One involved removing the firing pin mechanism from 90mm's (I believe) and there was also a round template thingy with a female receptacle that could receive the objective end of one side of a binocular that you could stick in the open breech (better method, less squinting) and both had the advantage of letting you just speak to the gunner so he could lay the crosshairs of the string on the selected right angle.

Then the gunner aligns the reticle and you have your rough sights set and you're ready to go to the range and bust some caps for zero.

Joe D. and Rob can clean up an details I've managed to screw up....

Although I may have stomped on some toes, ( ) I do know the 'string method', and have used it on a couple of occasions. The 'witness marks' on on end of the gun tube ( at 12 & 6 and 3 & 9 o'clock positions ) are the alignment marks for the string.

With the breech closed & the firing pin (firing probe on 120mm breech), use one side of binos (looking thru the firing pic 'hold') and direct the gunner to manually adjust the bore to the desired right angle. Then align the electronic / manual sights. THERE,.....see I know how to do it.

I saw that M48A5's and M60's used Pye-Watsons according to previous posts. I'm assuming that these two M60 barrels had these "tick-marks" at 12, 3, 6, and 9 o-clock for back-up, field expediant, string cross hair markings. Were the strings just simply attached with 100mph tape?

I saw that M48A5's and M60's used Pye-Watsons according to previous posts. I'm assuming that these two M60 barrels had these "tick-marks" at 12, 3, 6, and 9 o-clock for back-up, field expediant, string cross hair markings. Were the strings just simply attached with 100mph tape?

Jeff,

Yep, or spit (if using thread) , or gum, or tied on with another piece of string around the circumference...whatever. Just so's you get the crosshairs where they needs ta' be. Pre-Pye-Watson or what-have-you, this was not the "backup method", but the PRIMARY method (for a certain category of tanker known pejoratively to certain callous, insensitive Jedi-Tankers as "dinosaurs")

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